1. Field of the Invention
The present invention relates to a battery monitoring apparatus for monitoring a battery during start of an engine.
2. Description of Related Art
Since a vehicle battery deteriorates after long-term use, a jump-start of the engine of an own vehicle may need to be performed using electric power supplied from a rescue vehicle or the like when necessary.
There is known a technique in which a jump-start determination is made based on the voltage of the battery of an own vehicle to determine whether the engine of the own vehicle has been started normally using electric power of the battery of the own vehicle, or has been jump-started (that is, has been started using electric power supplied from a rescue vehicle).
Japanese Patent Application Laid-open No. 2001-107768 describes that an engine is determined to have been jump-started if the voltage of the battery of an own vehicle was higher than a predetermined threshold value immediately before starting the engine. The threshold value is set between the voltage of the battery when the engine is started normally, and the voltage of the battery when the engine is jump-started by being supplied with electric power from an alternator of a rescue vehicle.
However, the above described conventional technique has the problem as described in the following. In this conventional technique, if the engine of the rescue vehicle is stopped and accordingly the alternator of the rescue vehicle is out of operation, or if the alternator of the rescue vehicle is inhibited from generating electric power, there is a concern that the engine of the own vehicle may be determined to have not been jump-started, although it has been jump-started actually.
In vehicles provided with idling stop functionality, automatically stop of an engine is inhibited after the engine has been jump-started. Accordingly, if the jump-start determination is not made correctly, the idling stop function may be adversely affected.